Power transmission mechanism



v Feb. 7, 1939.

J. E. MCADAMS ET AL. POWER TRANSMISSION MECHANISM Filed March 5, 193eIlI s' sheets-sheet' 1y Feb. 7, 1939. J AE MCADAMS Er AL 2,145,942

POWER TRANSMISSION MECHANISM Filed Marrch, 1936 3 SheetS-fSheet 2 e .3 yj h3? H Y ./29 A I T; 25g* M TToQNays Fb. 7, 1939. A J. E. MoADAMs E? AL42,145,942

l POWER TK ANSMISSEON MECHANISM Filed March 5, 1936 3 Sheets-@Sheet 3 55`the mechanism shown in Fig. 1 .l

n Patented Feb. 7, 1939 PATENT OFFICE i POWER TRANSMISSION MECHANISM`Joseph E. McAdams, Springfield,v Ohio, and Warren. D. Burton, Pasadena,Calif., assignors to IThe Steel Products Engineering Company,Springfield, Ohio, a. corporation of Ohio ApplicationMarch 5, 1936,rSerial No. 67,244

6 Claims. '(Cl. 'Ill-125)r Our invention relates` to improvements inpower transmission mechanisms and is? especially adapted for use insupplying power from electric driving motors, or'other suitable' sourcesof power,

v: to stokers of the smaller type, such as are commonly` used" indomestic installations. Such f jsto'kers' frequently include a screwconveyer through whichcoal or's'imilar solid fuel is supplied tothecombustion-chamber of afurnace. It is 1'0k desirable that thefuel besupplied to the combustion chamber in relatively small increments,

, sincel the fuel bed isV thus maintained in a porousk condition sothat' air penetrates the same more K y readily. A more intimate mixtureof the air and fuel is' thusbrought about and consequently,

better' combustioncharacteristics are thereby l 'obtained'.` It isfthusdesirable that'. the driven f element for actuating the screwconveyer, or the ,-like; should receive periodic impulses giving thesamev a progressive step by step movement.

' 1 yIt `is an objectof our invention to provide a powerl transmissionmechanism of the type described which is adapted to periodically imparta series of driving impulses to a driven member adaptedto be connectedto the screw conveyer of a'stoker or the like, and which includesanark,rangement for selectively varying the number of such. ldrivingimpulses in each periodic series i thereof. y Anotherobject of ourinvention-is to provide I an Vimprovedy power transmission mechanism of's the typedescribed, which is rugged in construction, effective andquiet in` Operation, and which may be assembled as a compact unitarystructure Y V Ywithin a single enclosingA casing.

y `Further Objects and advantages of Vourinvention will become apparentas the following dej scription proceeds, and the features of noveltywhich characterize our invention are pointed out 40 withA particularityin the claims annexed to and forming apart of this specification.

4For Ya jbetter'understanding of our invention, `reference may be hadtothe accompanying drawings, 'inf which, l f `Figure 1 is a sideelevation partly in section of a power'transmission Vmechanismadaptedfor use with a domestic Stoker and embodying our invention.

Fig. 2is 'a detail View of a portion of the power transmission mechanismshown in Fig. land particularly illustrates Athe rrelative positions ofthe `parts thereof during the periodic-disconnection of :the drivenelement from the driving element.

f 3 is a sectional view alongr the line o f Fig. 4 is a sectional viewalong the line 4-4 of a portion of the mechanism shown in Fig.` 1.

Fig. 5 is an explodedy perspective view of a plurality of camsY includedin the mechanism shown in Figs. 1 to 4, inclusive. 5

While our invention is susceptible of various modifications and.alternative constructions, we have shown in the drawings and will hereindescribe in detail the preferred embodiment, but it is tobe understoodthat we'do not thereby intend 10 to limit the invention to the specificform disclosed, but on the other'hand intend to cover all modificationsand alternative constructions fall'- ing within the spirit and scope ofour invention.

Referring to the drawings, we have illustrated l5 ai power transmissionmechanism, embodying our invention, whichv is mounted as a compactunitary structure within an enclosing casing IIJ. The casing is providedwith a rear wall and integral side walls, the open end thereof beingclosed by a 20 removable cover I I which is secured thereto by a seriesof cap screws I2. Power is delivered to the power transmission mechanismbya driving element or drive shaft I3 extendingA therein and rotated bya suitable electric driving motor or the 25 like connected thereto. Adriven' element or driven shafty I4 also extendswithin the casing I0 andmay be connected to a screw conveyer of a stoker or similar mechanism tobe driven thereby. The driving shaft I3 is journaled in ball bearings 30I5 and I6, the outer races of which are held in position in suitablebores formed in the casing I0 by bushing rings I1 and I8, respectively.The driven shaft I4 is surrounded by a longitudinally extending quill orsleeve I9. A frangible connec- 35 tionis providedv between the sleeve I9and driven shaft I4, this connection being preferably in the form of ashear pin 20 extending through registering holes formed in the sleeve I9and driven shaft I4. If an excessive load is imposed on the 40 drivenshaft I Il, the pin 2U will be broken, thus disconnecting the shaft I4and sleeve I9 so that the parts o-f the power transmission mechanismwill not be subjected to the excessive load.

The sleeve I9 is journaled in suitable sleeve bearings formed by bosses2| and 22 formed on the rear wall of the casing I0 and cover II thereof,respectively. An antifriction type thrust bearing 23 is interposedbetween a shoulder 24 formed on the sleeve I9 and the inner wall of thecasing 5 cover II. The Outerend 25 of the driven shaft I4 is preferablysquared in order that the shaft may be rotated by a suitable wrench incase it becomes necessary to operate the mechanism by hand f 55 Theimproved power transmission mechanism which we have provided is adaptedto impart a series of driving impulses to the driven shaft I4 from thedriving shaft I3. In this way, a screw conveyer, for example drivenby'the shaft I4, moves successive increments of coal to the combustionchamber of a furnace. The driving impulses are imparted to the drivenshaft I4 by a suitable ratchet mechanism which includes a ratchet wheel26 rigidly secured to the sleeve I9 by a key 21 which engagescooperating keyways formed in the ratchet wheel 26 and sleeve I9. Theratchet wheel 26 is actuated in a counterclockwise direction, as viewedin Fig. 1, by a cooperating pawl 28 which is pivotally supported on thelower portion of a bifurcated oscillatable lever 29 by a pivot pin 39.The pawl 28 is provided with a downwardly extending weighted portion 3|which tends to maintain the same in operative engagement with theratchet wheel 26. A holding pawl 32, pivotally mounted on a pin 33, isbiased to a position of engagement with the ratchet wheel 26 by atension spring 34 in order to prevent clockwise movement of the ratchetwheel 26 as viewed in Fig. 1.

The side members of the bifurcated lever 29 are arranged on oppositesides of the ratchet wheel 26 and are loosely journaled on the sleeveI9. Thelever 29 isroscillated about the axis of the sleeve I9 and'drivenshaft I4 by a cam 35 which engages a roller 36 rotatably mounted on theupper end portion of the lever 29 by a pin 31. The roller 36 ismaintained in lengagement with the peripheral surface of the cam 35 by atension spring 38 secured at its opposite ends to the casing I and thelever 29. The cam 35 is rotated by a gear wheel 39 to which it isrigidly secured by a series of screws `4I). The cam 35 and gear wheel 39are mounted on a jack shaft 4I, the gear 39 being keyed thereto by a key42 which` engages cooperating keyways formed in the shaft 4I and gearY39. The shaft 4I is journaled in ball bearings 43 and 44, the outerraces of which are mounted in oppositely positioned bores formed in therear wall of the casing I0 and cover II thereof, respectively. The gear39 is connected to the driving shaft I3 by a worm 45.

, constant amplitude.

It will thus be seen that upon rotation of the driving shaft I3, thegear 39 and cam 35 secured thereto will be continuously rotated by theworm 45. Upon such rotation of the cam 35, the roller 36 `mounted on theupper end of the lever 29 follows the surface of the cam 35 due to thebias of the spring 38 and the lever 29 is thus continuously oscillatedabout the axis of the driven shaft I4 through an arc of substantiallyUpon each such oscillation of the lever 29, the pawl 28 is actuatedvinto engagement with successive teeth on the ratchet wheel 26 so thatthe latter is rotated in progressive steps. As a consequence, drivingimpulses or increments of rotative movement'are imparted to the drivenshaft I4. The teeth on the ratchet wheel 26 are preferably maderelatively long so that only about ten teeth are required to cover itsperiphery. Thus, the screw conveyor to which the driven shaft I4 isconnected is yturned through one full revolution of movement movementthereof and the bed of burning fuel will thereby be maintained in aporous condition that promotes eflicient combustion. Y

We have provided an improved arrangement for selectively varying thenumber of driving impulses imparted to the driven shaft I4 in a unit oftime or cycle of operation so that the total quantity of fuel, forexample, supplied by the stoker screw conveyer connected to the drivenshaft I4, may be selectively varied. This arrangement includes a detent46 having a beveled nose or cam portion 46aI engageable with a pin 41secured to the pawl 28 for lifting the pawl out of operative engagementwith the ratchet wheel 26. The detent 46 is rigidly secured to a pin 48rotatably and slidably mounted in a hole 49 formed in the casing II, asbest shown in Fig. 4.

The detent 46 is in turn moved into and out of operative position forengagement with the pawl 28 by an interrupting arrangement including aplurality of rotatable cams 50, I, 52 and 53 loosely journaled on thesleeve I9. I preferably provide a plurality of cams having cam surfacesof progressively different conguration in order that the detent 46 maybe selectively moved into engagement with any one of the cams so as toYvary the duration of the period during which the pawl 28 is maintainedout of operative engagement with the ratchet wheel 26. As best shown inFig. 5, the cams 50 to 53, inclusive, are disk shaped. The cam 53 has acam surface which extends entirely about the4 same while the cams 50, 5Iand 52 have notches or relieved portions 54, 55 and 56 formed thereon sothat the peripheral cam surfaces thereof are progressively longer. Thecams 50 to 53, inclusive, are rigidly secured together and also securedto a second ratchet wheel 51 by a series of rivets 58 extendf ingthrough registering holes formed therein. Substantially continuousrotative motion is imparted to the ratchet wheel 51 by a cooperatingpawl 59 pivotally secured to the oscillating lever 29 by pivot pin 60.When the lever 29 is oscilratchet wheel 51 so that -when the lever4 29again moves in a counterclockwise direction, the pawl 59 engages thenext tooth on the ratchet wheel '51, moving the same'in' acounterclockwise direction as viewed in Fig. 1. The pin 6I thus preventsthe pawl 59 from engaging any butthe next successive tooth on theratchet wheel 51 even though the pawl is oscillated a vdistance of twoor more teeth by the lever'29, since the pin maintains the pawl out ofcontact with other thanY the next successive tooth. The ratchet wheel 51is provided with a relatively large number of teeth and it will thus beseen thatrthe ratchet wheel 51 and its attached cams 56 to ,53,inclusive, are substantially continuously rol which rides on the camsurfaces of one of the adjacent cams 58 to 53,'inclusive. The pin 48, onwhich the detent 46 is mounted, is provided with amanual operatinghandle or knob 63, located exteriorly of the casing Il), whichfacilitates axial adjustment of the same so Ythat the detent 46 may beselectively positioned in operative relation with any one of the cams5|] to 53, inclusive. A notched plate 64 extending from the side of theoperating handle 63is selectively engageable with cooperating notches 65formed in a plate 66 so that the detent 46 may be maintained inalinement with the selected one'of the cams. A tension spring 61 securedto the detent 46 and to the l 27,14359'4`2 rcoverl ISI of theenclosingrcasing biases the detent 46 to a position of engagement with the cams;

- It` willl thus be seen thatif the detent 46 is j moved bythe operatinghandle 63 to theposirtion shown in Fig. 4, it will engage the cam 50.Then,` as the cam 50 is rotated by the ratchet Wheel 57 Yand pawl 59 thedetent 46 will be moved outwardly during the portion of the revolutionof the camk I)` in which they projection 62' is in Acontact with theraised cam surface of the cam 50. Then each time th'epaWl Ztilfmovesvfrom the position shown in Fig. 1` lto that' shown in Fig. 2r to engagethe-next tooth onthe ratchet wheel 26,

it is'lifted out of engagement with the ratchet Wheel' 26 by theelevated end of the detent 45 engaging the pin '41. Subsequently, whenthe projection 62kon the detent 46 moves into the relieved or notchedportion 54 of the caml 5I), the

n' detent 46 moves out of the path of the pin 4T on the pawl 28 so thatthe latter is again free -to en rgage successive teeth in the ratchetwhee1-25.y Theroperation is'substantially the same when the detent 46 ismoved into engagement with the cams 5I and 52 except that the intervalduring which the main pawl 28 is permitted to engage Y successive teethon its cooperating ratchet wheel 26 is shorter than inthe case ofthe cam58,'

Since'the cam 53 has no notched or relieved portion therein, the pawl 28is rendered entirely inoperative to move the ratchet wheel 26 when thedetent 46 is moved into contact with the 'cam 53.

In the operation of the mechanism described above, the driving shaft I3is rotated by a suitable y electric motor, or other source of power. The

" detent 46 is moved into engagement with one ofv the cams 50 to 53,inclusive, by the manual operating handle 63, corresponding to the parn'ticular rate of fuel-feed desired. The rotating o drive shaft I3 rotatesthe cam 35 through gear 39'and Worm 45. Rotation of the cam 35oscillates the lever 29 which in turn actuates the main Ypawl 28. toimpart a series of rotativeimpulses to the main ratchet Wheel 26,connected yto the driven shaft I4 by sleeve I9. The oscillation of thelever 29 also actuates pawl 59 which tion ofthe substantiallycontinuously rotating ratchet wheel 51 may be selectively varied.

. It will thus be seen that we have provided a simpleand effectivearrangement by meansY ofA whichv the number of 'driving impulsesimparted to the driven shaft I4 may be selectively varied. As

av consequence, the amount of fuel fed bythe jstoker to `the furnace maybe readily controlled. Atthe same time, the screw conveyer, or the like,of the stoker is always actuated by a series of'rotative impulses sothat the fuel is always l fedin increments to the furnace irrespectiveof f the total rate of feed.

` Although We have shown an embodiment of our f invention which isparticularly adapted for use l in connection with a stoker designed fordomestic use, We do not desire our invention to be limited to theparticular construction shown and described and we intend in theappended claims to cover all modifications Within the spirit vand scoperfiof our invention.

We claim as our invention:

l. A transmission mechanism comprising, in combination, av drivingelement, a'driven element, a ratchet wheel having a driving connectionWith Said driven element, a pawl vengageable with said ratchet wheel,means including said driving elementfor actuating said pawl to move saidratchet wheel, interrupting means including a detent engageable withsaid pawl for moving said pawl out of operative'engagement with saidratchet wheel, a" plurality of rotatably mounted cams having Camsurfaces of different configuration, cam follower means engageable withany selected one of said cams for actuating said interrupting means toperiodically maintain said detent out of engagementv said pawl forpredetermined ysequential intervals of time, and means includlratchetwheel', means including said driving element for actuating said pawl tomove said ratchet wheel, means for periodically maintaining said pawloutof engagement with said ratchet wheel for predetermined 'sequentialintervals of time, said last named means including a plurality ofrotatable cams having cam surfaces of different configuration and camfollower means engageable with any selected one of said cams foractuating said pawl out of engagement With said ratchet wheel, and meansincluding said driving element for substantially continuously rotatingsaid cams.

3. A transmission mechanism comprising, in combination, a drivingelement, a driven element, a ratchet Wheel having a driving connectionwith said driven element, an oscillatable lever, means including saiddriving element for oscillating said lever, a pawl actuated by saidlever and cooperating With said ratchet Wheel to actuate the same,interrupting means including a detent engageable with said pawl formoving said pawl out of operative engagement with said ratchet wheel, aplurality of rotatably mounted cams having cam surfaces' of differentconfiguration, cam follower means engageable with any selected one ofsaid cams for actuating said interrupting means to periodically maintainsaid detent out of engagement with said pawl for predeterminedsequential intervals of time, a second ratchet Wheel connected indriving relation with said cams, and means including a second pawlactuated by said lever and cooperating With said second ratchet wheel toactuate the same.

4. A unitary transmission mechanism comprising, in combination, anenclosing casing, a driving shaft and a driven shaft extending into saidcasing, a ratchet wheel mounted on said driven shaft and operativelyconnected thereto in driving relation, an oscillatable lever looselyyjournaled on said driven shaft, means including said vcams in drivingrelation, and a second pawl actuated by said lever and engageable withsaid second ratchet wheel to actuate the same.

5. A unitary transmission mechanism comprising, in combination, anenclosing casing, a driving shaft and a driven shaft extending into saidcasing, a sleeve mounted on said driven shaft and rigidly connectedthereto by a frangible connection, a ratchet Wheel mounted on saidsleeve and rigidly connected thereto, an oscillatable bifurcated leverloosely journaled on said sleeve and extending about said ratchet wheel,means including said driving shaft for oscillating said lever, a pawlpivotally mounted on said lever and cooperating with said ratchet Wheelto actuate the same, a pivotally mounted detent engageable with saidpawl to move the same out of operative engagement with said ratchetwheel, a plurality of disk shaped cams loosely journaled on said sleeveand having relieved cam surfaces thereon of progressively varyinglength, means including a manual operating handle located outside saidenclosing casing for selectively moving said detent into engagement Withsaid cams, a second ratchet Wheel loosely journaled on said sleeve andrigidly connected to said cams, and a .second pawl pivotally connectedto said lever and engageable with said second ratchet Wheel to actuatethe same. 1

6. A transmission mechanism comprising, in combination, a drivingelement, a driven element, a ratchet wheel having a driving connectionwith said driven element, a pawl engageable with said ratchet Wheel,means including said driving element for continuously actuating saidpawl through a constant amplitude of movement to move said ratchetwheel, means including a plurality of rotatably mounted cams having camsurfaces of different configuration adapted to cooperate individuallywith said paWl for periodically maintaining the same out of engagementwith said ratchet Wheel during a selected numberV of a predeterminedseries of actuations of said pawl, adjustment means for rendering anyselected one of said cams operative to control the engagement of saidpawl with said Yratchet Wheel, a second ratchet Wheel connected indriving relation with said cams, and means including a second pawlactuated by said driving member and cooperating with said second ratchetWheel to actuate the same. Y

JOSEPH E. MCADAMS. WARREN D.'BUR,TON.

n CERTIFICATE CORRECTION. Patent No'. 21LI5,9L;2 February 7, 1959.

JOSEPH E. MCADAMS, ET AL. It is hereby certified that error appearsv inthe printed specification of the above numbered patent requiringcorrection as follows; Page 5, second *I column, line 50, claim 2,before the word "cam" insert including; and thjt the said Letters Patentshould be read withthis correction therein'that the same may conform tothe record ofthe case in the Patent Office.

A. Sig-ned and sealed this 28th day of March, A, D. 1959.

Henry Van Arsdale.

(Seal) l i Acting Commissioner of Patents.,

